The present invention relates to a manifold for a gas burner that improves flame stability and burner turndown. More specifically, the present invention relates to a manifold for a gas burner that introduces gas perpendicularly to the airflow at a point of highest air velocity and lowest static pressure for improved mixing and also introduces gas axially near the center of the manifold to improve flame stability and burner turndown.
Conventional gas burners for use in furnaces, boilers, water heaters or other gas appliances mix gas, e.g., natural or LP gas, with air received from a fan or blower to form a mixture that is fed to a combustion head and ignited to form a flame along or adjacent to the combustion head. Generally, gas burners use a motor driven air blower to provide some or all of the air needed for combustion. Conventional gas burners have suffered from various drawbacks, which those in the art have sought to overcome. For example, some prior art burners do not completely combust all of the gas supplied to the burner. That is, although the gas and air mix sufficiently to ignite and produce a flame, some of the gas remains unburned and is vented along with the combustion products. This wastes gas and increases the cost of obtaining sufficient heat needed to operate the appliance with which the burner is utilized.
In addition, the goal of obtaining good mixing of the gas and air has led some in the art to increase the length of the combustion head or burner to increase the time during which the flowing gas and air may mix. In conventional burners, the length of the mixing chamber, as defined between the location at which the gas is emitted into the burner and the location at which the gas and air are substantially thoroughly mixed for combustion, can be as much as ten times as large as the diameter of the mixing chamber. Consequently, the manufacture of burners require a considerable amount of material which increases their size and cost. The increased size can present problems by limiting flexibility in utilizing the burner with various gas appliances.
Conventional gas burner designs also have attempted to produce an even, stable flame at the burner head, a desirable but often difficult feature to obtain. Prior art burners have included various devices to produce a stable flame that does not vary significantly along the length or around the burner head. For example, some burners have been provided with special inserts, e.g., cone-shaped orifice liner elements, in the burner to manipulate the flow of gas and air to obtain a relatively even flame profile. Including special inserts in the burners makes their manufacture more involved and costly.
Accordingly, a need exists for a gas burner that can produce an even, stable flame and is cost effective to make and operate.
Accordingly, it is an object of the present invention is to provide a burner with improved flame stability and burner turndown.
Another object of the present invention is to provide a burner that optimizes mixing of gas and air.
Still another object of the present invention is to provide a burner that optimizes mixing of gas and air by introducing gas perpendicularly to the airflow at a point of highest air velocity and static pressure.
Still another object of the present invention is to provide a burner that is cost effective to make and operate.
Yet another object of the present invention is to provide a burner that is versatile and can be used with various gas appliances.
The foregoing objects are basically obtained by providing a gas burner having a longitudinally extending blast tube with an open end and a burner head. The burner head includes a first surface that faces in a direction transverse to the longitudinally extending blast tube and toward the open end and a second surface that faces in a direction transverse to the longitudinally extending blast tube and away from the open end. A third surface extends between the first and second surfaces, with a first plurality of gas ports extending therethrough. A first passageway extends from the first surface to the second surface and is adapted to allow air to pass therethrough, and has a flame rod extending therethrough.
The foregoing objects are further provided by a diffuser assembly for a burner, including a first plate having a first opening and a first plurality of apertures adjacent the opening, the apertures adapted to allow gas to flow therethrough in an axial direction. A second plate is spaced from and oriented substantially parallel to the first plate and has a second opening. A radial surface extends between the first and second surfaces and has a second plurality of apertures, the second plurality of apertures adapted to allow gas to flow therethrough in a transverse direction relative to the first and second circular plates. A passageway extends between the first and second openings, the passageway adapted to allow air to pass therethrough, and has a flame rod extending therethrough.
The foregoing objects are further provided by a burner having improved stability control and turndown, including a blast tube having a first end and a second end. A fan is coupled to the blast tube, and adapted to drive air along the blast tube from the second end to the first end. A diffuser assembly is positioned within said blast tube and has a first circular plate, a second circular plate and a radial surface. The first circular plate faces in a direction of the blast tube first end and has a first plurality of gas ports extending therethrough and a first opening. The first plurality of gas ports is adapted to allow gas to flow therethrough in an axial direction. The second end faces in a direction of the blast tube second end and has a second opening. The radial surface extends between the first and second circular surfaces and has a second plurality of gas ports extending therethrough. The second plurality of gas ports is adapted to allow gas to flow therethrough in a radial direction. A passage extends between the first and second openings and is adapted to allow to air to pass therethrough, and has a flame rod extend therethrough.
Other objects, advantages, and salient features of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.